Sensor device and method for making thereof

ABSTRACT

A sensor device may include an electronic device that has at least one integrated circuit device and a MEMS sensor that are each monolithically integrated with a semiconductor substrate. The sensor device may include a suspension structure that suspends the MEMS sensor over a back cavity within the semiconductor substrate. The suspension structure may be springs or a spring structure formed from etching the front side of the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. patent application Ser. No.15/009,855, filed Jan. 29, 2016, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

Various embodiments relate generally to sensor devices and methods formanufacturing sensor devices.

BACKGROUND

Electronic devices may include micro-electro-mechanical systems (MEMS)are used in a variety of devices and applications. MEMS may include, forexample, a pressure sensor. The consumer pressure sensor market isbecoming mainly ASP driven. The main expense factor for today's pressuresensor modules is the quasi-standard open cavity LGA package which canrepresent 60% of the manufacturing costs. Generally it may be desired touse a low cost molded package in order to reduce manufacturing costs.Some MEMS, such as pressures sensors, are very sensitive to mechanicalstress. Thick silicone glue inside a package may be used to decouplemechanical stress from a MEMS stress is from the MEMS by thick siliconeglue inside the package. However, stress decoupling on package levelwith silicone glue is not possible in standard molded packages.Additionally, the mold compound can exert stress which depends onenvironmental factors such as humidity and temperature. As aconsequence, it is not possible to use molded pressure sensor packages.

SUMMARY

In various embodiments, a sensor device, may include an electronicdevice, which includes a semiconductor substrate having at least oneintegrated circuit and a MEMS sensor, the MEMS sensor including amembrane, a back cavity within the semiconductor substrate arrangedbelow the MEMS sensor and extending to a back side of the semiconductorsubstrate, and a suspension structure suspending at least the membraneof the MEMS sensor in the semiconductor substrate; a molding partiallyencapsulating the semiconductor substrate. The sensor device may furtherinclude a sensor port having an opening in the molding at a front sideof the substrate exposing at least the MEMS sensor membrane to anenvironment outside the sensor device. The at least one integratedcircuit and the MEMS sensor may be monolithically integrated in asemiconductor substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. The drawings are not necessarilyto scale, emphasis instead generally being placed upon illustrating theprinciples of the invention. In the following description, variousembodiments of the invention are described with reference to thefollowing drawings, in which:

FIG. 1 shows a cross-sectional view of an embodiment of a sensor deviceincluding at least one integrated circuit device and a MEMS sensormonolithically integrated according to at least one exemplaryembodiment;

FIG. 2 is a flow chart of a method for manufacturing a sensor deviceincluding at least one integrated circuit device and a MEMS sensormonolithically integrated according to at least one exemplaryembodiment;

FIGS. 3A-3J are views of stages of a substrate being processed to form asensor device according to at least one exemplary embodiment;

FIGS. 4A-4C show a cross-sectional, a top perspective view, and a topcross-sectional perspective view of a sensor device including at leastone integrated circuit device and a MEMS sensor monolithicallyintegrated on a substrate of according to at least one exemplaryembodiment;

FIG. 5A shows a perspective view of a suspension structure of asubstrate according to at least one exemplary embodiment; and

FIG. 5B is a graph showing indicating the strain or stress decoupling ofthe suspension structure of FIG. 5A according to at least one exemplaryembodiment.

FIGS. 6A-6C show substrates including conventional springs.

FIGS. 7A-7F show substrates including springs according to at least oneexemplary embodiment.

FIGS. 8A-8B show a substrate with springs according to at least oneexemplary embodiment.

DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific details and embodiments inwhich the invention may be practiced.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration”. Any embodiment or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs.

The word “over” used with regards to a deposited material formed “over”a side or surface, may be used herein to mean that the depositedmaterial may be formed “directly on”, e.g. in direct contact with, theimplied side or surface. The word “over” used with regards to adeposited material formed “over” a side or surface, may be used hereinto mean that the deposited material may be formed “indirectly on” theimplied side or surface with one or more additional layers beingarranged between the implied side or surface and the deposited material.

The term “connection” may include both an indirect “connection” and adirect “connection”.

When referring to semiconductor devices, at least two-terminal devicesare meant, an example is a diode. Semiconductor devices can also bethree-terminal devices such as field-effect transistors (FET), insulatedgate bipolar transistors (IGBT), junction field effect transistors(JFET), and thyristors to name a few. The semiconductor devices can alsoinclude more than three terminals. According to an embodiment,semiconductor devices are power devices. Integrated circuits may includea plurality of integrated devices.

In various embodiments a sensor device includes at least one integratedcircuit and a MEMS sensor which are both monolithically integrated in asemiconductor substrate or wafer. In accordance with variousembodiments, suspension structures described herein are incorporated orformed in the substrate/wafer. The suspension structure may be spring(s)or a spring formed in the substrate or wafer.

FIG. 1 shows a cross-sectional view and representation of a sensordevice 1 including at least one integrated circuit device and a MEMSsensor monolithically integrated in or on a substrate according to anexemplary embodiment. In FIG. 1, the sensor device includes anelectronic device 5. The electronic device 5 may, for example, be asemiconductor chip or a part thereof. The electronic device 5 shown inFIG. 1 includes a semiconductor substrate 10 having at least oneintegrated circuit device 15 and a MEMS sensor 20. In accordance withvarious embodiments, the integrated circuit device 15 and the MEMSsensor 20 are each monolithically integrated in the semiconductorsubstrate 10.

The substrate 10 and other semiconductor layer(s) or wafer(s) describedherein can be made of any suitable semiconductor material. Examples ofsuch materials include, without being limited thereto, elementarysemiconductor materials such as silicon (Si), group IV compoundsemiconductor materials such as silicon carbide (SiC) or silicongermanium (SiGe), binary, ternary or quaternary III-V semiconductormaterials such as gallium arsenide (GaAs), gallium phosphide (GaP),indium phosphide (InP), gallium nitride (GaN), aluminum gallium nitride(AlGaN), indium gallium phosphide (InGaPa) or indium gallium arsenidephosphide (In—GaAsP), and binary or ternary II-VI semiconductormaterials such as cadmium telluride (CdTe) and mercury cadmium telluride(HgCdTe) to name few.

In various embodiments, the at least one integrated circuit device 15may be an application-specific integrated circuit (ASIC). The at leastone integrated circuit may also include semiconductor devices (e.g.,transistors, diodes) or other circuit elements, such as, for example,resistors, capacitors, etc. fabricated using known semiconductorprocesses.

The MEMS sensor 20 may include one or more sensing elements 25, such asmembrane or any other type of sensor element. In various embodiments,the MEMS sensor 20 may be a pressure sensor with a membrane/diaphragm.

The substrate 10 of FIG. 1 includes a back cavity 22 located below theMEMS sensor 20. That is the MEMS sensor 20 at least partially covers theback cavity. The back cavity 22 is formed within the substrate 10 andextends from a bottom surface 10 b of the substrate to within apredefined distance of the MEMS sensor.

The substrate 10 of FIG. 1 includes a suspension structure 50 (notshown). The suspension structure 50 can suspend the MEMS sensor 20 toprovide mechanical stress decoupling.

The suspension structure 50 of FIG. 1 can be formed and reside withintrenches 40. The trenches 40 may at least partially surround the MEMSsensor 20. As shown in FIG. 1, the trenches 40 extend from a front-side10 a of the substrate 10 to reach the back cavity 22.

The electronic device 5 of FIG. 1 is partially encapsulated. A molding70 covers sidewalls of the substrate 10 as well as sections of thefront-side 10 a of the substrate 10 so as to form an opening or sensorport 80 in the molding. The opening or sensor port 80 provides anopening in the molding 80 that exposes a section of the front side 10 aof the substrate 10 and to the MEMS sensor 25 and further, provides anopening or passageway between the MEMS sensor membrane and anenvironment outside the sensing device 1. For example, in the case of apressure sensor, a sensor port such as the sensor port 80 can expose themembrane of the pressure sensor to an environment of the sensing device1.

The molding 70 may be formed by any suitable molding process, such as,for example, using film assisted molding (FAM) technology in oneexemplary embodiment. In another embodiment, the sensor port 80 may beformed using through lithography, using, for example, using SU8photoresist to create the sensor port 80 through etching.

FIG. 1 further shows electronic device 5 mounted to a carrier 100. Thesubstrate 10 may be attached or adhered to the carrier 100 by means ofan adhesive 60, such as for example, conductive and non-conductive epoxyglue, die attach film, silicone glue, and/or a wafer back coating, toname a few.

In various embodiments, the suspension structure 50 can provide stressdecoupling on the chip level or package level. The suspension structure50 may be in the form of spring(s). The trenches 40 may be formed,through a trench etching process that produces the spring(s) or springstructure. The trenches 40, that is, may define the springs providingsuspension to the MEMS sensor 20.

FIG. 2 shows a flow chart for manufacturing a sensor device including aMEMS sensor and one or more integrated circuit devices eachmonolithically in a substrate of the sensor device according to one ormore exemplary embodiments.

FIGS. 3A-3G are cross-sectional views a semiconductor substrate invarious stages in forming a sensor device with monolithically integratedMEMS sensor and one or more integrated circuit devices according toexemplary embodiments.

Referring to FIG. 2, a semiconductor substrate is provided including atleast one integrated circuit and a MEMS sensor. In at least oneembodiment, the at least one integrated circuit and the MEMS sensor aremonolithically formed in the semiconductor substrate. The at least oneintegrated circuit and the MEMS sensor can be formed at one side of thesemiconductor substrate, such as, for example, a front side of thesubstrate. The at least one integrated circuit may be formed using anysuitable and well known semiconductor and MEMS manufacturing techniques,e.g., deposition, etching, lithography, etc. In embodiments, the atleast one MEMS sensor and the at least one integrated circuit may beformed in any appropriate or suitable order.

FIG. 3A shows of a portion 310 of a semiconductor substrate 300. Thatis, the semiconductor substrate 310 may be disposed on or over one ormore other semiconductor layers, as is shown later. The semiconductorsubstrate 300 may be a section of a wafer, such as after singulation.The substrate portion 310 includes a logic field section 310 a laterallyadjacent to a sensor field section 310 b. The logic field section 310 amay contain or include at least one logic device, such as an ASIC, FPGA,etc. The sensor field section 310 b may contain at least one sensordevice, e.g., a MEMS sensor.

Further, the upper portion 310 may initially include a partially formedsensor device, e.g., pressure sensor or other type of sensor. In thiscase, the sensor field 310 b includes electrodes terminals 320 and afixed electrode 330 therebetween. The electrode terminals 320 may bemade formed using any suitable material such as, silicon oxide, in oneexample. Further, as shown, a sacrificial layer 340 may be formed overthe upper substrate portion 310. In the embodiment of FIG. 3A, thesacrificial layer 340 includes layers of nitride and carbon that aredisposed over or on the logic field 310 a and the sensor 310 b and usedfor forming a diaphragm, or other types of sensor elements. In otherembodiments, the sacrificial layer may include one or more other typeslayers including other materials, such as, for example silicon oxide,polyimide, and one or more metals (e.g. aluminum).

Next, in the embodiment of FIG. 3B, the sacrificial layer 340 has beenpatterned to form a patterned sacrificial layer 340 a. The sacrificiallayer 340 may be etched by removing one or portions of the sacrificiallayer 340 over the sensor field 310 b. The sacrificial layer 340 can bepatterned using any suitable etching or lithography process ortechnique.

After forming the patterned sacrificial layer 340 a, a membrane layer350 can be formed or provided over the substrate portion 310 as shown inthe embodiment of FIG. 3C. The membrane layer 350 is shown depositedover the sensor field 310 b and deposited over the logic field 310 a. Aresist 360 is also shown selectively deposited over the membrane layer350 for use in patterning the membrane layer 350. The membrane layer 350may be any suitable material, including polysilicon as one example.

The embodiment of FIG. 3D shows the upper substrate portion 310including a MEMS sensor, e.g., a MEMS pressure sensor 375 and a logicdevice 380. In FIG. 3D, the membrane layer 350 in FIG. 3C has beenpatterned. The membrane layer 350 may be patterned through alithographic process or any other suitable or viable method. Also asshown in FIG. 3D, the patterned sacrificial layer 340 a has been removedleaving a cavity 355. As a result, the patterned membrane layer 350 is afree or substantially free-hanging membrane 370. In accordance withexemplary embodiments, the may be removed through etching. In oneexample where the sacrificial layer includes a carbon layer, the carbonlayer can be etched and thereby removed using and oxygen-plasma etching.In other embodiments, a wet etch may be used, at least in part. Forexample, hydrofluoric acid may be used to remove a silicon oxide layerof the sacrificial layer.

The materials used or produced in the membrane patterning, e.g., resist,residue, etc. can also be removed. After removal of such materials, oneor more back-end-of-line (BEOL) layers may be formed or deposited overor on the front side of the substrate portion 310 and becoming a part ofthe substrate 300. The one or more BEOL layers may include structuressuch as one or more dielectric layers, one or more conductive layers,one or more interconnect structures, and the like, to name a few.

In the embodiment of FIG. 3E a logic device 380 and a MEMS sensor 375are each monolithically integrated in or on the semiconductor substrate300. As shown, the substrate 300 includes one or more BEOL layers 390disposed over a semiconductor layer or wafer 385, and e.g. disposed overthe logic device 390 over one or more sections of the MEMS sensor 375.However, the membrane 370 of the MEMS sensor 375 is uncovered orexposed. That is, in FIG. 3E, the one or more BEOL layers 390 are notformed over at least a section of the MEMS sensor 370 including themembrane 370.

The semiconductor layer 385 may include any suitable of semiconductormaterial, such as silicon and the like.

Referring back to FIG. 2, a semiconductor substrate has been providedwith a monolithically integrated MEMS sensor and at least one integratedcircuit, and then a back cavity in the semiconductor substrate can beformed at 220 and a suspension structure from the semiconductorsubstrate at 230. The back cavity and suspension structure may beseparately, in any order, e.g., the back cavity can be formed first andthe suspension structure second or vice versa. Further, the back cavity325 and suspension structure can also be formed simultaneously or nearlysimultaneously. In accordance with various embodiments, the cavity andsuspension structure may be formed using an one more etching processes,such as, for example using a reactive ion etching process e.g., deepreactive ion etching (DRIE).

In forming the back cavity and/or the suspension structure, thesubstrate may be placed on a temporary carrier. For example, thefront-side of the substrate may be attached to a temporary carrier whenthe back cavity is being formed and/or the back side of the substratemay be attached to a temporary or permanent carrier when the front sidesuspension structure is being formed.

The embodiment of FIG. 3F shows the substrate 300 of FIG. 3E including aback cavity 325 and suspension structure 392. The suspension structure392 includes one or more trenches 394. The trenches 394 composing thesuspension structure 392 and the back cavity may be formed through deepreactive ion etching (DRIE). Prior to etching, a resist 395 may bedeposited on the substrate for etching.

The embodiment of FIG. 3G shows the substrate 300 of FIG. 3F afterremoval of any resist or other materials used or produced by etching.The trenches 392 extend from a front side 301 a of the substrate 300 tothe back cavity 325. The back cavity 325 extends from a back side 301 bof the substrate 300 to a predetermined a height in the substrate 300,such as, for example, to or within a predetermined height in thesemiconductor layer 385.

The one or more trenches 392 may be etched or formed so as to produce asuspension structure 394 that provides mechanical stress decoupling tothe MEMS sensor 375. The suspension structure 392 suspends the MEMSsensor 375 in the substrate 300 over the back cavity 325.

In accordance with one or more exemplary embodiments, the suspensionstructure 392 may be in the form of one or more mechanical springsformed in and/or from the substrate 300. That is the spring may includethe various layers composing the substrate 300, such as, for example,include parts or sections of one or more of metallization layers,dielectric layers, passivation layers, semiconductor layers, etc.

FIG. 3H is a top cross-sectional view of substrate 300 along the lineA-A in FIG. 3G. In FIG. 3H, the suspension structure 392 is shownsurrounding the membrane 370 of the MEMS sensor 375. The suspensionstructure 392 includes trenches 394 that have been patterned. Thetrenches 394 define a spring structure 396. The spring structure 396extends vertically through the substrate 300. As shown in FIG. 3G andFIG. 3H, the spring structure 396 includes one or more vertical sections394 a of the substrate 300. The vertical sections 394 a are at leastpartially separated from one or more other vertical sections of thesubstrate 300 by one or more spaces or gaps in the substrate. Thespring(s) or sprint structure 396 is adjacent and/or between thetrenches 394.

FIG. 5A shows a partial perspective view of trenches 394 and springstructure 396 according to various embodiments. FIG. 5B shows asimulation of the absolute strain of a spring structure of FIG. 5A inthe XY plane (the XY plane being parallel to a surface at the top side301 a of the substrate 300 facing away from the back cavity 325).

Referring back to FIG. 3H, the spring structure 396 may include orprovide an electrical connection between the MEMS sensor 375 and thelogic device 380. As previously noted, the spring structure 396 caninclude one or more metallization layers, any of which may electricallyconnect to the MEMS sensor 375 or a part thereof (e.g., electrode 330).Similarly, the spring structure 396 may electrically connect to anycomponent or device, either within or outside the substrate 300.

The spring structure 396 and trenches 394 shown in FIG. 3H extend fromthe back cavity 325 towards the front side 301 a of the substrate 300.That is, the trenches 394 may extend through one or more semiconductorlayers, conductive or metallization layers, dielectric layers, etc. Inother embodiments, the trenches 394 and/or spring structure 396 may notextend all the way to the substrate front side 301 a.

FIG. 3H shows one possible pattern arrangement including two trenches394 a, 394 b. In FIG. 3H each of the trenches 394 includes trenchsegments connected to each other at right-angles. Each trench 394 a and394 b have a spiral-like structure where each trench 394 a and 394 b isboth inner and outer to each with respect to the sensor 370 and that thesensor 370 is surrounded by at least one of the trenches 394. Of coursethe number of trenches used to form the springs 396 or suspensionstructure 392 can vary. Further, the pattern of the trenches 394 mayalso vary. That is the trenches 394 need not be formed or arranged instraight-line segments, but may include one or more curved, wavy, orother types of sections. Further the trenches 394 may not be formed orarranged in a spiral-like pattern. In short, other variations may berealized.

In the embodiment of FIG. 3I, the substrate 300 of FIG. 3G is mounted orattached to a carrier 100. The carrier 100 may be an insulating or anelectrically conductive carrier, and/or may function as a heat sink.

As previously explained the substrate 300 may include one or moreinterconnect structures. In FIG. 3I an interconnect structure iselectrically connected to carrier 100 via a bond wire 315 and bond pad316. In other embodiments, the substrate 300 may include one or moreadditional interconnect structures that may later be connected to othercomponents or devices that are not shown.

Referring back to FIG. 2, after forming a suspension structure and aback cavity, at 240 a sensor port can be formed by or through at leastpartially encapsulating the substrate with a mold. The sensor port is anopening in the mold at the front side of the substrate and exposing atleast a portion of the MEMS sensor (e.g., membrane) to an environmentoutside the sensor device.

In various embodiments, the sensor port through an encapsulationprocess. Any suitable encapsulation process may be used, including afilm-assisted molding (FAM) process, as one example. A FAM process mayuse one or two mold films (e.g., plastic films) in a mold. In oneexample of a FAM process, a mold film is sucked down into the innersurfaces of a mold (e.g., culls, runners, cavities, etc.) before thelead frames or substrates (e.g., the products to be encapsulated) areloaded into the mold. This is followed by the usual transfer moldingprocess. The molding material may first be liquefied by heat andpressure, and then forced into closed mold cavities and held there underadditional heat and pressure until the molding material is solidified orcured. After curing the molding material, the mold is opened with thenow encapsulated product(s) then being unloaded. Next, the vacuum isremoved and the film is transported across one length of the mold orrenewed and a new cycle can start. A FAM process makes it possible tocreate open or windowed packages by means of placing inserts in thebottom and/or top mold.

The embodiment of FIG. 3J shows the substrate 300 of FIG. 3I in apartial mold environment during a FAM process. That is, the substrate300 is located within a mold that is partially shown. FIG. 3J shows anupper mold part 77 with a mold film 75 is vacuum drawn or sucked onto asurface 77 a of the upper mold part 77. In accordance with variousembodiments, the substrate 300 is sealed in a mold so that the uppermold 77 disposed against the upper side 301 a of the substrate 300.

After the substrate 300 is placed in the mold, molding material 70 canbe injected into the mold. In FIG. 3J, the molding material 70 at leastpartially encapsulates the substrate 300 and covers one or moresidewalls of the substrate 300 and one or more sections of the upperside 301 a of the substrate 300. An insertion or protrusion section 78of the upper mold 77 presses against the upper side 301 a of substrate300 to create a window. When the molding material 70 is injected, theprotrusion section 78 located over the MEMS sensor 375 prevents themolding material 70 from forming over the MEMS sensor 375.

FIGS. 4A-4C show several views of an electronic device 400 according tovarious embodiments. The device 400 includes the substrate 300 of FIG.3J after encapsulation and mounted on a carrier 100. The moldingmaterial 70 has been cured or hardened and contains a sensor port 80.The sensor port 80 provides an opening or passage between the MEMSsensor 375 and environment outside the electronic device 100. The sensorport 80 can allow pressure waves, sound waves, light, or other phenomenaoriginating from can outside the electronic device 400 to reach the MEMSsensor 375, and e.g. the membrane 350, (or other sensing element inother embodiments).

In accordance with various embodiments the spring structure 392 isconfigured to absorb and/or reduce stresses. The spring structure 392can absorb and/or reduce the effect of vibrations occurring in thedevice 400. For example, the spring structure 392 can absorb or reducemechanical stresses, caused or produced as a result of thermal expansionand/or contraction of device components or materials. Furthermore, thespring structure reduces or eliminates mechanical stresses resultingfrom mounting the device on a larger PCB (printed circuit board).

During an operation of the sensor device 400 or other sensor devicesdescribed herein, pressure or acoustical waves may enter through thesensor port 80 and reach the MEMS sensor 375 to cause vibration of themembrane 370. The vibrating membrane 370 can cause corresponding changesto an electrical field between the membrane and the electrode 330 thusproducing an electromagnetic field. This resulting electromagnetic fieldmay create or generate an electric signal corresponding to the pressurewave or acoustic wave entering the sensor port 80 and causing themembrane 370 to vibrate. This electric signal may then be processed byany device, e.g., logic device 380 or another external device (notshown).

While in various embodiments, MEMS sensors have been described aspressure sensors, other types of MEMS sensors maybe used instead. Forexample the MEMS sensor 375 need not be a pressures sensor but may beany other appropriate MEMS sensor, such as, an ultrasound transducer, inone example. In this regard, the membrane 370 may instead be other typesof appropriate sensing elements. In accordance with various embodiments,MEMS sensors described herein may be a pressure sensor, gas sensor, amicrophone, or the like, to name a few.

FIGS. 6A-6C show views of a substrate 600 including various conventionalsuspension structures. The substrate 600 may be a semiconductorsubstrate (e.g., silicon) and may be, for example, in the form of a chipframe.

FIG. 6A is a partial perspective three-dimensional view of the substrate600 including a MEMS device. A section of the substrate 600 has beenremoved for visual illustrative reasons. The area occupied or to beoccupied by the MEMS device, or other device may be referred to asdevice area, designated 620 in this embodiment. The device area 620 isconnected to a suspension structure 625 that includes a plurality ofsprings 610 in one known configuration. FIGS. 6B and 6C are top views ofchip frame 600 depicting different configurations of suspensionstructure 625. As shown in FIGS. 6A-6C, the springs 610 are depicted asline segments for illustrative purposes, but would otherwise have avertical dimension, e.g., a height or depth.

As noted, in FIG. 6A a section or part of the substrate 600 includingsome of the springs 610 have been removed so that inner arrangement ofthe springs 610 can be more clearly depicted.

FIGS. 6A-6C depict conventional suspension structures 625 includingsprings 610. Each of these springs 610 extend predominantly in a singledimension or in a single dimension between the device area 620 and thesubstrate 600. That is, each of the springs 610 are limited in the sensethat one or major portions or springs extend only in one direction. Inother words, each the springs 610 generally do not or cannot providemechanical decoupling or significant decoupling in more than one lateraldimension.

As one example, each of the springs 610 shown in FIG. 6B has one majorspring portion or segment 611. The spring portion 611 only extends in asingle direction with the spring portion 611 facing and being parallelto a peripheral side of the MEMS device/area 620. However, none of thesprings extend around the MEMS device/area 620. That is none surround orenfold around any of the corners or bends of the MEMS device/area 620.Similarly as shown in FIG. 6C, the spring segments 611 and 613 arefolded over each other and also only extend in a single direction.

In accordance with exemplary embodiments of the present disclosure,suspension structures or springs described herein may have differentconfigurations with improved performance characteristics, especiallywith regard to providing mechanical decoupling.

According to exemplary embodiments of the present disclosure, FIGS.7A-7F each depict a top view of semiconductor substrate 700 respectivelywith springs 710 a-710 f. The springs 710 a-710 f may be formed inaccordance with any suitable manufacturing techniques, includingmanufacturing techniques described herein. The substrate 700 mayconnected, e.g., electrically and/or physically connected to otherdevice or elements. In some embodiments, the substrate 700 may furtherinclude one or more other devices, for example, at least one integratedcircuit that is monolithically integrated in the substrate 700. Thesubstrate 700 may include a device, for example, a MEMS device that isformed and/or located in device area 700. The device, for example MEMSdevice, other devices, and/or the springs 710 a-170 f may be formed inaccordance with embodiments described herein. Other types of devices,for example other than MEMS devices, may be located and/or formed in thedevice area 720. A cavity or back cavity may be formed in the substrate700 below the device area.

In the exemplary embodiment shown in FIG. 7A, the substrate 700 includesa plurality of springs 710 a. Each of the springs 710 a includes atleast two spring segments or portions, designated 711 a and 713 a. Thespring portions 711 a and 713 a can be considered together as anL-shaped portion. These portions meet each other at 90 degrees orsubstantially 90 degrees. An L-shaped portion such as the one formedfrom spring portions 711 a and 713 a may partially enclose, enfold, orsurround a section of the device area. In FIG. 7A, the L-shaped portionincluding portions 711 a and 713 a wraps around a corner or a section ofthe device area 720.

Further in the embodiment of FIG. 7A, the spring portions 711 a and 713do not extend in a lateral direction (in the XY plane) beyond or pastmore than one than one edge, side or distinct boundary of the devicearea 720 to which the respective portion 711 a or 713 faces. Forexample, the spring portion 711 a only extends past dashed line “a”which corresponds to a boundary or peripheral side of the device area720. Similarly, the spring portion 713 b only extends past dashed line“b”, corresponding to another boundary or peripheral side of the devicearea 720.

Further, the spring segments 711 a and 713 a may each be parallel to andface a different side or section of the periphery of a device area, asshown in FIG. 7A with respect to the device area 720. The spring 710 aincludes a spring portion that connects or attaches the spring portion711 a to the device area 720 and includes another portion that connectsor attaches the spring portion 713 a to the substrate 700.

The springs 710 a as arranged in FIG. 7A do not overlap each other inthe sense that each of the springs 710 a covers or masks a differentsection or area of the periphery of the device area 720. The springs 710a of FIG. 7A appear identical or having the same dimensions. Howeverthis is not necessarily so, and in other embodiments one or more of thesprings 710 a may have different dimensions, e.g., have lengths orthicknesses that differ from at least one other spring. The dimensionsthe springs 710 a may depend at least in part on the dimensions of thedevice area 720.

In the exemplary embodiment of FIG. 7B, the substrate 700 includes aplurality of springs 710 b. Each of the springs 710 b includes anL-shaped spring portion including segments or spring portions 711 b and713 b. The spring portions 711 b and 713 b meet each other atright-angles or approximately 90 degrees. As shown, the spring segmentsor spring portions 711 b and 713 are orthogonal or substantiallyorthogonal to each other. In other embodiments, the angles in which thespring portions meet may vary, for example up to 5-10% deviation from aright angle in one example.

Each of the spring portions 711 b and 713 b of FIG. 7B extend past orbeyond at least one of the outermost boundary or side/edge of the MEMSdevice area 720. For example, the spring portion 711 b in FIG. 7Bextends past a dash-line “b” which corresponds to a boundary of thedevice area.

Further, the spring portion 713 b extends beyond two sides or outermostboundaries of the device area 720. In other words, the spring portion713 b may have a length greater than a width or length of the MEMSdevice area 720 from an overhead perspective or within the XY plane. TheMEMS device area 720 in FIG. 7B is depicted as rectangular (which is notnecessarily so) with the spring portion 713 b having a length greaterthan a length of the corresponding side of periphery of the device area720 to which the spring portion 713 b faces. As shown, the springportion 713 reaches or meets the substrate 700.

Further, the spring portion 711 b may extend beyond an outermostboundary or edge of the device area 720 so as to reach or meet thespring portion 713 b. The spring portion 711 b extends past a second endor extreme of the same boundary of the device area so as to reach theportion 713 b. That is the spring portion 711 b also has a lengthgreater than greater than a length of the side/boundary of area 720facing the spring portion. In other embodiments, the length of thespring portion 711 b may be less, and may begin a position correspondingto an end the side/boundary of the device area facing the spring portion711 b.

The spring 710 b in FIG. 7B includes a spring portion that connects orattaches spring portion 711 b to the device area 720 and furtherincludes another portion that connects or attaches the portion 713 b tothe substrate 700.

In the exemplary embodiment shown in FIG. 7C, the substrate 700 includesa plurality of springs 710 c. The springs 710 c may be similar to thesprings 710 b of FIG. 7B, but arranged differently. The springs 710 c,like the springs 710 b, each include an L-shaped portion includingspring segments or portions 711 c and 713 c that are orthogonal orsubstantially orthogonal to each other. In FIG. 7B, the springs 710 b donot overlap, with each of the springs 710 b covering, masking, or facingdifferent sides or areas of the periphery of device area 720. However inthe exemplary embodiment of FIG. 7C, the springs 710 c are arranged inan intertwined spiral or spiral-shaped pattern, and more specifically inan intertwined square or rectangular-like spiral pattern. In otherembodiments, the springs 710 c may be arranged in other type of spiralpatterns, including, for example, in an intertwined circular or ovalspiral pattern and the like, to name a few.

In the embodiment of FIG. 7C, each of the springs 710 c begins from adifferent part, e.g., section, boundary, or side of the periphery ofMEMS area 720. Further, the springs 710 c are arranged so that eachperipheral side of the device area 720 is laterally covered or masked byspring segments or portions of the respective springs 710 c. The springs710 c enclose the device area 720. Each of the springs 710 c as shownincludes an L-shaped spring portion that faces or at least partiallymasks sides of the periphery of the MEMS device area 720.

The exemplary embodiment shown of FIG. 7D depicts the substrate 700including a plurality of springs 710 d. The springs 710 d of FIG. 7D aresimilar to the springs 710 c of FIG. 7C in that they are also arrangedin an intertwined spiral or spiral-like pattern. The springs 710 d ofFIG. 7D, as arranged, surround the device area 720. The springs 710 d,in other embodiments, may also be arranged in other types of spiralpatterns as previously described herein.

In the embodiment of FIG. 7D, the device area 720 is rectangular, eachperipheral side of facing or being covered or masked by spring segmentsor portions of the springs 710 c. The springs 710 d includes a C-shapedportion. The springs 710 d, at least partially face or cover three sidesor sections of the periphery of the device area 720. As can be seen, adifference between the springs 710 d and springs 710 c are that thesprings 710 d have a C-shaped portion instead of a single L-shapedportion. As shown, each of the springs 710 d the C-shape portionincludes spring segment or portions 711 d, 713 d, and 715 d. TheC-shaped portion of springs 710 d can be described as two L-shapedportions, sharing a common spring segment 713 d.

In the embodiment of FIG. 7D, the spring portion 711 d connects orattaches to the device area 720 via another spring segment or portion.Further, the spring portion 715 d of FIG. 7D directly connects orattaches to the substrate 700. In other embodiments, the spring portion715 d may indirectly connect to the substrate via one or more otherspring segments.

While the exemplary embodiments of FIGS. 7C and 7D respectively showsprings 710 c and 710 d bending around a device area 720 two times (withL-shaped portion) and three times (with a C-shaped portion), in otherembodiments the springs may further extend out and spiral around thedevice area 720 in the same spiral manner. For example, in the casewhere a MEMS device area is rectangular like in FIG. 7D, a spring mayextend and spiral around the device area 720 multiple times.

Further, while in each of the embodiments of FIGS. 7C and 7D a set offour springs are depicted, the amount of springs may vary. For example,a substrate such as substrate 700 may include only one, two, three, fouror more distinct springs that spiral around a device area 720.

The exemplary embodiment of FIG. 7E depicts the substrate 700 includingsprings 710 e with folds. Each of the springs 710 e includes springfolds 712 e and 714 e. As shown, the spring fold 712 e includes springportions 711 e, 716 e, and 713 e. The spring portion 713 e can beconsidered as “folded” over the spring portion 711 e, or vice versa. Thespring portion 716 e may be considered a “bend” in the fold 712 e thatconnects the spring portion 711 e to the spring portion 713 e. Similarlythe spring fold 714 e includes spring segments or portions 715 e, 717 e,and 718 e. In the spring 710 e, the spring fold 712 e connects orattaches to the spring fold 714 e. More specifically in the embodimentof FIG. 7E, the spring portion 713 e of the spring fold 712 e meets orconnects to the spring portion 715 e of the spring fold 714 e.

As shown in the exemplary embodiment of FIG. 7E, the spring fold 712 eis orthogonal or substantially orthogonal to the spring fold 714 e. Thatis the spring portions 711 e and 713 e of the spring fold 712 e areorthogonal or substantially orthogonal to the spring portions 715 e and717 e of the spring fold 714 e.

Furthermore, each of the springs 710 e partially enclose or surround theperiphery of the device area 720. In the embodiment of FIG. 7E, thedevice area 720 is rectangular with each spring fold 712 e and 714 e offacing and/or arranged parallel to a different side of the periphery ofthe device area 720.

The exemplary embodiment of FIG. 7F also depicts the substrate 700 withsprings 710 f having folds. However, each of the springs 710 f includesa single fold 712 f instead of two folds as in the case of the springs710 e. The fold 712 f of FIG. 7F includes an inner spring portion 711 fand an outer spring portion 713 f. The spring portions 711 f and 713 fare L-shaped spring portions as previously discussed herein. The outerspring portion 713 f covers or folds over the inner spring portion 711f. Since the spring fold 712 f includes two L-shaped spring portions,the spring fold 712 f extends in two orthogonal or substantiallydirections within the xy plane.

In FIG. 7F, the springs 710 f together surround the periphery of thedevice area with each of the springs 710 f partially enclosing orsurrounding the periphery of the device area 720.

In accordance with exemplary embodiments, trenches may be created toform or define springs 710 a-710 f. For example, trenches may be formedthrough deep reactive ion etching (DRIE) as previously explained ordiscussed in various embodiments disclosed herein. The trenches, likethe springs 710 a-710 f may be formed vertically, or in directionperpendicular to the displayed XY plane. The trenches may define thestructure, shape(s), and/or configuration of the springs 710 a-710 f.For example, in the embodiments of FIGS. 7A and 7B, the trench ortrenches 730 includes or provides gaps next to the spring portions. Ingeneral, the gaps between the spring portions or between a springportion and device area 720 may be the same or may be different fromeach other. In general, the trenches and the spring or spring portionsare configured as straight, and not curved in the XY plane. However,variations in the shape the springs, spring portions or trenches, mayinclude minor or negligible bending with curved or arched sections andthe like may be due to normal deviations resulting from manufacturingprocesses.

Similarly the width of the gaps between the spring portions 711 a and713 a and the substrate 700 may be the same or different from eachother.

While in the embodiments of FIG. 7A-7B, show a certain amount or numberof springs, for example a set of four springs 710 a are shown in FIG.7A, the number of springs 710 a used in a substrate may vary and may beany suitable amount. Moreover, the springs 710 a-710 f may be used witheach other, some of the springs 710 a-710 f may be incorporated witheach other and/or with other types of springs in a same substrate. Thesprings 710 a-710 f may be used as the springs in connection with thedevices previously described herein, for example, devices described inconnection with FIGS. 1-4C.

As noted, sensor chips, such as pressure sensor chip and the like inmolded packages experience thermal expansion. As a result, the substrateand/chip can experience bending due to thermal expansion and othereffects. The decoupling by spring presented herein, for example springs710 a-710 f provide significantly better decoupling than known springs.

FIG. 8A shows a substrate 800 with a pair of springs 810 a, which aresimilar to the springs 710 a of FIG. 7A, while FIG. 8B shows thesubstrate 800 with a pair of springs 810 b that are similar to springsof FIG. 6C. The amount of decoupling provided by the springs 810 a, orthe stress on the device area 820, e.g., the MEMS device, is reduced bya factor of approximately 50,000. By contrast, the amount of stressreduced by the springs 810 b to the device area 820 is onlyapproximately 2000.

It is noted, for example, when an external force makes the chip bend, incase where there is no stress decoupling (e.g., no trenches and no backcavity), the resulting stress acting on the MEMS device can be forexample, 1 MPa. (This would be the sum of the absolute normal stresscomponents in x and y directions). However when a stress decouplingstructure or feature is introduced, this may result in the stress beingreduced to e.g. 0.2 MPa. In this example, the resulting stress reductionfactor in this example would be a factor 5.

That is, the structure of configuration of the springs 810 a, as well asthe springs of FIGS. 7A-7B provide similar or better mechanicaldecoupling and stress reduction.

In various embodiments a sensor device includes a substrate thatincludes a MEMS sensor and at least one integrated circuit aremonolithically integrated in a substrate, the substrate that have athickness of approximately 100 μm to approximately 1000 μm.

In various embodiments, the substrate may include a suspension structurethat suspends the MEMS sensor over a back cavity. In variousembodiments, the suspension structure at least partially surrounds aperimeter of the membrane of the MEMS sensor.

In various embodiments, the suspension structure includes one or moresprings formed within the substrate that are adjacent and/or between oneor more trenches of the semiconductor substrate. In various embodiments,the one or more trenches extend from the front side of the semiconductorsubstrate to the back cavity, with the dimensions of trenches having awidth of approximately 1 μm to approximately 100 μm, and a depth ofapproximately 10 μm to approximately 500 μm.

In various embodiments, the substrate is mounted on a carrier.

In various embodiments, the trenches of the suspension structure areformed through deep reactive ion etching (DRIE).

In various embodiments, the sensor device including a molding partiallyencapsulating the semiconductor substrate. The molding can have anopening for a sensor port that exposes at least a portion of the MEMSsensor, e.g., a membrane/diaphragm, to an environment outside the sensordevice.

In various embodiments, the sensor port is formed by at least partiallyencapsulating the substrate using a film assisted molding process.

In various embodiments, the suspension structure electrically connectsthe MEMS sensor to the at least one integrated circuit. In variousexemplary embodiments, the at least one integrated circuit includes anapplication specific integrated circuit (ASIC).

In various embodiments, the MEMS sensor is a pressure sensor, and insome embodiments includes a diaphragm or membrane made out ofpolysilicon.

In various embodiments, a sensor device, may include an electronicdevice, which includes a semiconductor substrate having at least oneintegrated circuit and a MEMS sensor, the MEMS sensor including amembrane, a back cavity within the semiconductor substrate arrangedbelow the MEMS sensor and extending to a back side of the semiconductorsubstrate, and a suspension structure suspending at least the membraneof the MEMS sensor in the semiconductor substrate; a molding partiallyencapsulating the semiconductor substrate. The sensor device may furtherinclude a sensor port having an opening in the molding at a front sideof the substrate exposing at least the MEMS sensor membrane to anenvironment outside the sensor device. The at least one integratedcircuit and the MEMS sensor may be monolithically integrated in asemiconductor substrate.

In various embodiments, the sensor device the suspension structure mayinclude a spring structure formed within the semiconductor substrate.The suspension structure may at least partially surround a perimeter ofthe membrane of the MEMS sensor. The spring structure includes springsformed from the substrate between one or more trenches of thesemiconductor substrate. The one or more trenches can extend from thefront side of the semiconductor substrate to the back cavity.

In various embodiments, the electronic device is mounted on a carrier.The sensor chip may be attached to the carrier by an adhesive. In someembodiments, the suspension structure electrically connects the MEMSsensor to the at least one integrated circuit device.

The sensor device, in some embodiments, may include the at least oneintegrated circuit includes, for example, an application specificintegrated circuit (ASIC).

In various embodiments, the MEMS sensor is a pressure sensor. The atleast one integrated circuit can be electrically coupled to the carrier,for example, via a bond wire that may be encapsulated within themolding.

In accordance with various embodiments, back cavities described hereinmay be rectangular or rectangular-like. For example the with dimensionsof the back cavity may range from approximately 50×50 μm² toapproximately 1000×1000 μm². In accordance with various embodiments,back cavities described herein may circular or circular-like with adiameter from approximately 50 μm to approximately 1000 μm. In variousembodiments, the back cavities may have a depth from approximately 10 μmto approximately 500 μm.

In accordance with various embodiments, trenches formed in a substrate,such as trenches that may at least partially surround a MEMS sensor mayhave a width of approximately 1 μm to approximately 20 μm and may have adepth of approximately 10 μm to approximately 500 μm.

In accordance with various embodiments, adhesives described herein mayinclude conductive epoxy glue, non-conductive epoxy glue, die attachfilm, silicone glue, and/or a wafer back coating, and combinationsthereof.

In accordance with various embodiments, sacrificial layers describedherein may include one or more layers of nitride, carbon, silicon oxide,polyimide, and of one or more metals, such as aluminum.

In exemplary embodiments of the present disclosure, a device includes asubstrate a semiconductor substrate including a device. In variousembodiments the device is a MEMS device. In various exemplaryembodiments, the MEMS device is monolithically integrated within thesubstrate.

The substrate may further include a back cavity within the semiconductorsubstrate arranged below the MEMS device, and includes a suspensionstructure that suspends and provides mechanical decoupling to at least aportion of the MEMS device in the semiconductor substrate. In exemplaryembodiments of the present disclosure, the suspension structure includesone or more springs, wherein the one or more springs are defined by oneor more trenches formed within the semiconductor substrate.

In exemplary embodiments, at least one spring of the one or more springsincludes at least one L-shape portion. The at least one L-shape portionof the at least one spring may at least partially surround a verticalouter surface or periphery of the MEMS device. The L-shape portion ofthe at least one spring may include a first spring section and a secondspring section that are each respectively substantially parallel a firstside or section and a second side or section of the periphery of theMEMS device. In various embodiments, the first and second springsections may be orthogonal to each other.

In various embodiments, the first spring section of the L-shaped portionof the at least one spring extends beyond at least one edge of the firstside of the periphery of the MEMS device, and wherein the second sectionof the L-shaped portion of the at least one spring extends beyond atleast one edge of the second side of the periphery of the MEMS device.

In various embodiments, the first spring section or the second springsection of the L-shaped portion of the at least one spring extends orconnects to the semiconductor substrate.

In various embodiments, the first spring section of the L-shaped portionof the at least one spring of has a length greater than a length of thefirst side the periphery of the MEMS device.

In various embodiments, the second spring section of the L-shapedportion of the at least one spring of has a length greater than a lengthof the second side of the periphery of the MEMS device.

In various embodiments, the at least one spring including the at leastone L-shape portion further includes a spring section extending from theL-shape portion to the MEMS device.

In various embodiments, the at least one spring comprising the at leastone L-shape portion further including a further spring section extendingfrom the L-shape portion to the semiconductor substrate.

In various embodiments, the one or more trenches defining the one ormore springs vertically extend from the front side of the semiconductorsubstrate to the back cavity.

In various embodiments, the back cavity extends to a back side of thesemiconductor substrate.

In exemplary embodiments of the present disclosure, a device includes asemiconductor substrate includes a MEMS device. In various embodiments,the device includes a back cavity within the semiconductor substratearranged below the MEMS device, and a suspension structure suspendingand providing mechanical decoupling to at least a portion of the MEMSdevice in the semiconductor substrate, wherein the suspension structureincludes comprising a plurality of springs, wherein the pluralitysprings are defined by one or more trenches formed within thesemiconductor substrate.

In various embodiments, each of the plurality of springs each includes afirst spring portion and a second spring portion, wherein the firstspring portion is joined to or connects to the second spring portion ata right angle or substantially a right angle.

In various embodiments, each of the plurality of springs includes athird spring portion, wherein the third spring portion extends in adirection parallel to a direction either the first spring portion or thesecond spring portion extends.

In various embodiments, the plurality of springs is arranged in anintertwined spiral pattern.

In various embodiments, the periphery of the MEMS device has four sides,and wherein each of the plurality of springs begins or attaches to at adifferent respective side of the periphery of the device.

In various embodiments, each of the plurality of springs includes afirst fold and a second fold, wherein the first fold and the second foldeach includes a set of two spring portions parallel to each other andseparated from each other by a gap. Further, in various embodiments, foreach spring, the spring portions of the first fold are perpendicular orsubstantially perpendicular to the spring portions of the second fold.

In various embodiments, the periphery of the MEMS device includesvertical sides or sections and wherein the plurality of springs includesa first spring and a second spring that surround vertical sides orsections of the MEMS device.

In various embodiments, the springs and/or spring portions may becurved, arched, or straight, e.g., portions be spring portions having anarched, curved, or straight shape.

In various embodiments, springs are arranged in straight orsubstantially straight-line spring portions. The springs having straightor substantially straight spring portions may be favorable or economicalin terms of taking up area or space.

While the invention has been particularly shown and described withreference to specific embodiments, it should be understood by thoseskilled in the art that various changes in form and detail may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims. The scope of the invention is thusindicated by the appended claims and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced.

What is claimed is:
 1. A device, comprising: a semiconductor substratecomprising a MEMS device; a back cavity within the semiconductorsubstrate arranged below the MEMS device, and a suspension structuresuspending and providing mechanical decoupling to at least a portion ofthe MEMS device in the semiconductor substrate, wherein the suspensionstructure comprises one or more springs, wherein the one or more springsare defined by one or more trenches formed within the semiconductorsubstrate, wherein at least one spring of the one or more springscomprises at least one L-shape spring portion, wherein the at least oneL-shape spring portion at least partially surrounds a periphery of theMEMS device.
 2. The device of claim 1, wherein the MEMS device ismonolithically integrated within the substrate.
 3. The device of claim2, wherein the one or more trenches defining the one or more springsvertically extend from a front side of the semiconductor substrate tothe back cavity.
 4. The device of claim 2, wherein the back cavityextends to a back side of the semiconductor substrate.
 5. The device ofclaim 1, wherein the L-shape spring portion of the at least one springcomprises a first section and a second section that are eachrespectively substantially parallel to a first side and a second side ofthe periphery of the MEMS device.
 6. The device of claim 5, wherein thefirst and second sections are orthogonal to each other.
 7. The device ofclaim 5, wherein the first section of the L-shaped spring portion of theat least one spring extends beyond at least one edge of the first sideof the MEMS device, and wherein the second section of the L-shapedspring portion of the at least one spring extends beyond at least oneedge of the second side of the MEMS device.
 8. The device of claim 7,where the first section or the second section of the L-shaped springportion of the at least one spring extends to the semiconductorsubstrate.
 9. The device of claim 5, wherein the first section of theL-shaped spring portion of the at least one spring has a length greaterthan a length of the first side the MEMS device.
 10. The device of claim5, wherein the second section of the L-shaped spring portion of the atleast one spring has a length greater than a length of the second sidethe MEMS device.
 11. The device of claim 1, wherein the at least onespring comprising the at least one L-shape spring portion furthercomprises a section extending from the L-shape spring portion to theMEMS device.
 12. The device of claim 1, wherein the at least one springcomprising the at least one L-shape spring portion further comprises afurther section extending from the L-shape spring portion to thesemiconductor substrate.
 13. The device of claim 1, wherein the at leastone L-shape spring portion of the at least one spring includes one ormore spring portions being substantially straight.
 14. The device ofclaim 1, wherein the at least one L-shape spring portion of the at leastone spring includes one or more spring portions including an arch shape.15. A device, comprising: a semiconductor substrate comprising a MEMSdevice, wherein the MEMS device is monolithically integrated within thesubstrate; a back cavity within the semiconductor substrate arrangedbelow the MEMS device, and a suspension structure suspending andproviding mechanical decoupling to at least a portion of the MEMS devicein the semiconductor substrate, wherein the suspension structurecomprises a plurality of springs, wherein the plurality of springs aredefined by one or more trenches formed within the semiconductorsubstrate, wherein each of the plurality of springs comprises a firstspring portion, a second spring portion, and a third spring portion,wherein the first spring portion is joined to the second spring portionat a substantially right angle and further and wherein the third springportion extends in a direction parallel to a direction either the firstspring portion or the second spring portion extends, and wherein theplurality of springs is arranged in an intertwined spiral pattern. 16.The device of claim 15, wherein a periphery of the MEMS device comprisesfour sides, and wherein each spring portion begins at a differentrespective side of the MEMS device.
 17. A device, comprising: asemiconductor substrate comprising a MEMS device; a back cavity withinthe semiconductor substrate arranged below the MEMS device, and asuspension structure suspending and providing mechanical decoupling toat least a portion of the MEMS device in the semiconductor substrate,wherein the suspension structure comprises one or more springs, whereinthe one or more springs are defined by one or more trenches formedwithin the semiconductor substrate, wherein at least one spring of theone or more springs comprises at least one L-shape spring portion,wherein the at least one spring comprising the at least one L-shapespring portion further comprises a section extending from the L-shapespring portion to the MEMS device.
 18. A device, comprising: asemiconductor substrate comprising a MEMS device; a back cavity withinthe semiconductor substrate arranged below the MEMS device, and asuspension structure suspending and providing mechanical decoupling toat least a portion of the MEMS device in the semiconductor substrate,wherein the suspension structure comprises one or more springs, whereinthe one or more springs are defined by one or more trenches formedwithin the semiconductor substrate, wherein at least one spring of theone or more springs comprises at least one L-shape spring portion,wherein the at least one spring comprising the at least one L-shapespring portion further comprises a further section extending from theL-shape spring portion to the semiconductor substrate.
 19. A device,comprising: a semiconductor substrate comprising a MEMS device, whereinthe MEMS device is monolithically integrated within the substrate; aback cavity within the semiconductor substrate arranged below the MEMSdevice, and a suspension structure suspending and providing mechanicaldecoupling to at least a portion of the MEMS device in the semiconductorsubstrate, wherein the suspension structure comprises a plurality ofsprings, wherein the plurality of springs are defined by one or moretrenches formed within the semiconductor substrate, wherein each of theplurality of springs comprises a first spring portion, a second springportion, and a third spring portion, wherein the first spring portion isjoined to the second spring portion at a substantially right angle andfurther and wherein the third spring portion extends in a directionparallel to a direction either the first spring portion or the secondspring portion extends, and wherein each of the plurality of springscomprises a first fold and a second fold, wherein the first fold and thesecond fold each comprises a set of two spring portions parallel to eachother and separated from each other by a gap, and wherein for eachspring, the set of two spring portions of the first fold isperpendicular to the set of two spring portions of the second fold. 20.The device of claim 19, wherein the MEMS device comprises vertical sidesand wherein the plurality of springs comprises a first spring and asecond spring so that the first spring and second spring surroundvertical sides of the MEMS device.